We do know quite a bit about how proteins fold in the cell, though of course there is likely still a lot to discover there. Chaperones are known for a long time now, and there's been plenty of research on them.

true, I was just thinking in terms of interpreting the word "fold" in many of the articles currently circulating

That's like saying "it's not known how stars form" because obviously we have not lived for a billion years to see a star form fully. We haven't seen a single Protein molecule fold fully, but we're pretty sure we know how it does (though some details are kinda murky).

my ephasis should be that much of "protein folding" is reffering to the final folded conformation and not the biological process of the protein actually folding